package com.atguigu.web;

import com.atguigu.pojo.Book;
import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import com.atguigu.service.BookService;
import com.atguigu.service.impl.BookServiceImpl;
import com.atguigu.utils.WebUtils;
import com.google.gson.Gson;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.math.BigDecimal;
import java.util.HashMap;
import java.util.Map;

/**
 * @author 徐州城
 * @version 1.0
 */
public class CartServlet extends BaseServlet {
    private BookService bookService = new BookServiceImpl();


    //加入购物车
    protected void addItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1、获取请求的参数 商品编号
        int id = WebUtils.parseInt(req.getParameter("id"), 0);
        //2、调用bookService.queryBookById(id)：book得到图书的信息
        Book book = bookService.queryBookById(id);
        //3、把图书信息，转换为CartItem商品项
        CartItem cartItem = new CartItem(book.getId(), book.getName(), 1, book.getPrice(), book.getPrice());
        //4、调用Cart.addItem(CartItem)；添加商品项
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        //因为cart是共享的，所以需要把 cart保存入Session域中
        if (cart == null) {
            cart = new Cart();
            req.getSession().setAttribute("cart", cart);
        }
        cart.addItem(cartItem);

        //最后一个添加商品的名称
        req.getSession().setAttribute("lastName",cartItem.getName());

        //5、重定向原来商品所在的地址页面
        resp.sendRedirect(req.getHeader("Referer"));
    }

    //删除商品项
    protected void deleteItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取商品编号
        int id = WebUtils.parseInt(req.getParameter("id"), 0);
        //获取购物车对象
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        if (cart != null) {
            //删除了购物车商品项
            cart.deleteItem(id);
            //重定向原来购物车展示页面
            resp.sendRedirect(req.getHeader("Referer"));
        }
    }

    //清空购物车
    protected void clear(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1、获取购物车对象
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        if (cart != null){
            //清空购物车
            cart.clear();
            //重定向原来购物车展示页面
            resp.sendRedirect(req.getHeader("Referer"));
        }
    }

    //修改商品数量
    protected void updateCount(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1、获取请求的参数 商品编号、商品数量
        int id = WebUtils.parseInt(req.getParameter("id"),0);
        int count = WebUtils.parseInt(req.getParameter("count"),1);
        //2、获取Cart购物车对象
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        if (cart != null){
            //修改商品数量
            cart.updateCount(id,count);
            //重定向原来购物车展示页面
            resp.sendRedirect(req.getHeader("Referer"));
        }
    }

    protected void ajaxAddItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1、获取请求的参数 商品编号
        int id = WebUtils.parseInt(req.getParameter("id"), 0);
        //2、调用bookService.queryBookById(id)：book得到图书的信息
        Book book = bookService.queryBookById(id);
        //3、把图书信息，转换为CartItem商品项
        CartItem cartItem = new CartItem(book.getId(), book.getName(), 1, book.getPrice(), book.getPrice());
        //4、调用Cart.addItem(CartItem)；添加商品项
        Cart cart = (Cart) req.getSession().getAttribute("cart");
        //因为cart是共享的，所以需要把 cart保存入Session域中
        if (cart == null) {
            cart = new Cart();
            req.getSession().setAttribute("cart", cart);
        }
        cart.addItem(cartItem);

        //最后一个添加商品的名称
        req.getSession().setAttribute("lastName",cartItem.getName());

        //6、返回购物车总的商品和最后一个添加的商品名称
        Map<String,Object> resultMap = new HashMap<>();
        resultMap.put("totalCount",cart.getTotalCount());
        resultMap.put("lastName",cartItem.getName());

        Gson gson = new Gson();
        String json = gson.toJson(resultMap);
        resp.getWriter().write(json);
    }



}
